Investments (Amortized Cost and Aggregate Fair Value of Debt Securities, by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Investments [Abstract]
Available-for-sale Securities, Due in one year or less, Amortized Cost	$ 3,232
Available-for-sale Securities, Due in one year or less, Fair Value	3,291
Available-for-sale Securities, Due after one year through five years, Amortized Cost	15,624
Available-for-sale Securities, Due after one year through five years, Fair Value	15,986
Available-for-sale Securities, Due after five years through ten years, Amortized Cost	34,761
Available-for-sale Securities, Due after five years through ten years, Fair Value	35,867
Available-for-sale Securities, Due after ten years, Amortized Cost	43,837
Available-for-sale Securities, Due after ten years, Fair Value	45,310
Available-for-sale securities, Amortized Cost	97,454	$ 92,077
Available-for-sale Securities, Fair Value	100,454
Held-to-maturity Securities, Due in one year or less, Amortized Cost	1
Held-to-maturity Securities, Due in one year or less, Fair Value	1
Held-to-maturity Securities, Due after one year through five years, Amortized Cost	39
Held-to-maturity Securities, Due after one year through five years, Fair Value	41
Held-to-maturity Securities, Due after five years through ten years, Amortized Cost	86
Held-to-maturity Securities, Due after five years through ten years, Fair Value	95
Held-to-maturity Securities, Due after ten years, Amortized Cost	1,946
Held-to-maturity Securities, Due after ten years, Fair Value	2,038
Held-to-maturity Securities, Amortized Cost	2,072	2,439
Held-to-maturity Securities, Fair Value	$ 2,175	$ 2,504